Noel Fielding and Sandi Toksvig are returning to our screens for the double-bill, along with judges Paul Hollywood and Prue Leith.
With eight classic GBBO contestants returning over two episodes to create Christmas-themed confectionary, one episode will feature four contestants from the 2016’s Bake Off.
Returning from the BBC’s final season is Selasi Gbormittah, Val Stones, Benjamina Ebuehi, and Rav Bansal.
The second GBBO episode will feature child welfare office Sandy Docherty from 2015 and quarter finalist Paul Jagger from the same year.
Prison governor Rob Billington, the runner up from season two, is returning, along with season four’s military wife Beca Lyne-Pirkis.
This will be the first time these eight retro bakers would have presented to new judge Prue, who was left red faced after prematurely tweeting the reveal of GBBO 2017’s Winner.
Ahead of last month’s final, which saw Sophie Faldo crowned the first champion on Channel 4, the 77-year-old tweeted: “No one told me judging a #gbbo final would be so emotional. I wanted them all to win. Bravo Sophie.”
Her co-judge Paul has since admitted the blunder may have caused a dent in the Bake Off’s finale ratings.
“I think we could have had much more,” he told Radio Times.
The Great Christmas Bake Off airs on Channel 4 next month.